The ROSAT PSPC surveys were generated by SkyView as mosaics from publically available PSPC observations. The surveys include all data available through March 1, 1997. This includes the vast majority of ROSAT PSPC observations. Filter observations and observations taken during the verification phase in 1991 were not included in either set. The details of the generation of the surveys are discussed in a companion document. Basically the counts and exposure from all observations were added and then an intensity map was generated as the ratio of the two.

The smaller cut-offs allow users to distinguish point sources in fields where a bright source may have been towards the edge of one observation and near the center of another. In these cases the source appears fuzzy due to the poor resolution of ROSAT near the edge of the field of view. This comes at the cost of a substantial reduction in the fraction of the sky covered. Counts and exposure maps are included for users who may need this information (e.g., to do statistical analysis).

The global organization of the surveys is similar to the IRAS survey. Each map covers an area of 2.5°;x2.5°; with a minimum overlap of 0.25°;. To cover the entire sky would require over 10,000 maps. However due to lack of coverage only approximately 4000-6000 maps are actually populated. Users asking for reqions where there is no ROSAT coverage may get a blank region returned.

Detailed information regarding the creation of the ROSAT suveys can be found in the ROSAT PSPC Generation Document. Provenance: Observational data from NASA Goddard Space Flight Center, mosaicking of images done by SkyView.. This is a service of NASA HEASARC.